Apparatus for classifying sand or like granular material



J. 27, 1942. J. M CLOUD ETAL 2,270,954

APPARATUS FOR CLASSIFYING SAND OR LIKE GRANULAR MATERIAL Filed Dec. 26, 1959 5 Sheets-Sheet 1 2 l i ol l l I I Jan. 27, 1942. J. E. M cLouD EFAL 21,

APPARATUS FOR CLASSIFYING SAND 0R LIKE GRANULAR MATERIAL Filed Dec. 26, 1939 3 Sheets-Sheet J96 r I. jy We ZWZZCQM The Jan. 27, 1942. J. E. McCLOUD ETAL APPARATUS FOR CLASSIFYING SAND OR LIKE GRANULAR MATERIAL I5 Sheets- Sheet 3 Filed Dec. 26, 1939 IIIIIHIIIIHIIIIII NIILVHllIl-HIIIIHHIIIIIIIIIIHlIlll Patented Jan. 27, 1942 APPARATUSFOR CLASSIFYING SAND OR LIKE GRANULAR MATERIAL Joseph E. McCloud, Maywood, -Ill., and Albert Williams, Cleveland, Ohio, assignors to Webster Manufacturing, Inc., Tiflin, Ohio, a corporation of Ohio Application December 26, 1939, Serial No. 310,862

8 Claims.

The present invention relates generally to apparatus for classifying sand or like granular material while it is immersed in a body of water.

More particularly the invention relates to that type of classifying apparatus which is adapted to have the sand and water flow through it after a preliminary screening of the sand to reduce the grains thereof to a predetermined maximum size and operates during flow or passage of the water and sand therethrough to separate or remove the fine grains of sand from the coarse or heavy grains.

' One object of the invention is to provide a sand classifying apparatus of this type which is of new and improved construction and has certain advantages over, and is more efficient in sand classifying apparatus of the type under consideration which comprises an open bottom receptacle with a receiving hopper at the upper portion thereof for the sand and water and a plurality of horizontally extending transversely slotted flexible strips in the bottom portion thereof for supporting the sand upon entry of it and the water into the receptacle, and also comprises a plurality of weir-equipped fiumes in the upper central portion of the receptacle for efiecting discharge of the water and fine particles of sand from the receptacle after passage of the water through the receptacle and deposit of the coarse or heavy grains of sand on the flexible strips.

Another object of the invention is to provide a sand classifying apparatus of the last mentioned character in which the transversely slotted flexible strips in the bottom portion of the receptacle are adapted after a suitable quantity of coarse sand grains have accumulated thereon to flex downwards into an open position wherein such coarse grains are permitted to drop or pass downwardly through the open bottom of the receptacle.

Another object of the invention is to provide a sand classifying apparatus of the type and character under consideration which in addition to the open bottom receptacle with the receiving hopper, the transversely slotted flexible strips I and the discharge fiumes, comprises a tank under and around the receptacle and conveyor means in the tank for discharging from the tank the coarse grains of sand which drop or pass downwards through the open bottom of the receptacle ;upon opening or downward flexure of the strips.

A further object of the invention is to provide a sand classifying apparatus of the aforementioned type and character in which the weirs on the fiumes are individually vertically adjustable in order that some may be elevated with respect toothers when it is desired to increase the velocity of the water as it flows through the receptacle into the fiumes and thus cause the discharge of intermediate sized grains of sand from the receptacle via the fiumes and the collection on the strips and within the tank of only extremely coarse or large sized grains of sand.

A still further object of the invention is to provide a sand classifying apparatus of the hereinbefore described type and character which includes a novel deflector and baffle arrangement in the receptacle whereby the water is caused to flow through the receptacle and into the fiumes in an efficient manner in connection with sand classification and in addition includes in associated relation with the receptacle, novel means for ridding the tank of any foam which accumulates within the tank during operation of the conveyor means.

Other objects of the invention and the various advantages and characteristics of the present sand classifying apparatus will be apparent from a consideration of the following detailed description.

The invention consists in the several novel 'features which are hereinafter set forth and are more particularly defined by claims at the conclusion hereof.

being broken away and other parts being shown in section for purposes of illustration;

Figure 2 is a side View of the receptacle;

Figure 3 is a vertical transverse section taken on the line 33 of Figure 1 and illustrating in detail the design of the interior of the tank of the apparatus and the arrangement of the screw conveyors which constitute the means for discharging from the tank the coarse grains of sand which drop or pass downwards through the bottom of the receptacle upon downward flexure of the transversely slotted strips at the bottom of the receptacle;

Figure 4 is an enlarged vertical transverse section taken on the line l-lof Figure 1 and illustrating in detail the arrangement and design of the transversely slotted flexible strips in the bottom portion of the receptacle and showing the manner in which such strips flex downwards into an open position when an appreciable amount of coarse sand grains accumulate there- Figure 5 is an enlarged transverse section taken on the line 55 of Figure 1 and disclosing the design and construction of the flumes whereby the water and fine sand grains are discharged from the receptacle after flow or passage therethrough; I

Figure 6 is an enlarged vertical longitudinal section taken on the line 66 of Figure 3 and showing not only the arrangement and design of the flumes and the deflector and baflle means, but also the manner in which the sand carrying water flows through the receptacle and into the fiumes; and

Figure 7 is a horizontal section on the line 'i'! of Figure 6.

The apparatus which is shown in the drawings constitutes the preferred embodiment of the invention. It is designed primarily to )classify sand or like granular material while the sand or material is immersed in a body of water and after a preliminary screening of the sand or material to reduce the grains thereof to a predetermined maximum size, and comprises a receptacle 8 and a tank 9. The receptacle is adapted to receive the sand and water from a trough, pipe, or other delivery medium (not shown) and is designed and adapted to have the classifying of the sand carried out in it. The tank 9 surrounds and underlies the receptacle 8 and, as hereinafter described, receives the coarse or heavy grains from the receptacle after the sand within the receptacle has been classified as the result of removal or separation of the fine grains of sand from the coarse ones. The apparatus is preferably operated continuously when it is in use.

The tank 9 is horizontally elongated and consists of a pair of laterally spaced parallel plate metal sides i and l I, a substantially flat bottom wall l2, and a flat end wall l3. The bottom wall I2 is upwardly inclined at a comparatively small angle (approximately 25), as shown in Figure 1, and is connected at the side margins thereof to the bottom margins of the sides l0 and II. The end wall I3 extends at right angles to the bottom wall l2 and is suitably joined at the bottom margin thereof to the lower end margin of the bottom wall l2. The sides In and ll extend vertically. They are suitably connected to the side margins of the end wall It and serve with the bottom wall [2 and said end wall l3 to hold or retain a column of water within the tank. The tank is held in place by means of a box-like angle iron frame [4 consisting of longitudinal bars, upright bars, and crossbars, and this frame, as shown in Figure l, is adapted to rest on a floor or other supporting surface. One portion of the upper margin of the side I0 is bent outwardly to form a horizontally extending flange l5 and a corresponding upper marginal portion of the side- II is bent outwards to form a horizontally extending flange l6. These two flanges are coplanar and serve to reinforce the sides of the tank against bending. They also serve, as hereinafter described, as a supporting medium for the receptacle 8. The grains of sand which are discharged into the tank 9 from the receptacle 8 are removed or discharged from the tank by means of a pair of screw conveyors l1. These conveyors are arranged in side by side relation and overlie and extend lengthwise of the bottom wall I2 of the tank. The lower ends of the shafts of the two conveyors extend through holes in the bottom portion of the end wall [3 and are journaled in bearings l8 which, as shown in Figure 1 are disposed exteriorly of, and are secured directly to the bottom portion of the end wall l3. The upper ends of the conveyors project a small distance beyond the upper end margin of the bottom wall 12 and are supported by a bracket structure IS. The latter extends between and is secured to the sides In and II of the tank and includes a pair of bearings 20 in which are journaled the upper'ends of the shafts of the conveyors. Drive of the conveyors is effected by means of a power driven cross shaft 2|, a pair of bevel gears 22, and a pair of bevel gears 23. The cross-shaft is journaled in suitable bearings on the bracket structure l9 and has the bevel gears 22 fixed thereto. The bevel gears 23 are fixed to the upper ends of the shafts of the screw conveyors and mesh with, and are driven by, the bevel gears 22. The gears 22 and 23 are so arranged that when the cross-shaft 2| is driven the two screw'conveyors I! are so rotated or driven that they serve to move the sand in the bottom of the tank upwardly along the bottom Wall [2 and then discharge such sand over the upper end of the bottom wall. Such end is bent downwards, as shown in Figure 1, and constitutes a discharge chute. The upper ends of the screw conveyors and the upper end of the bottom wall I2 of the tank are located above the level of the column or body of water in the tank with the result that the sand which is subjected to the conveying action of the conveyors is dewatered prior to discharge over the upper end of the bottom wall. The two screw conveyors l1 constitute means for elevating and conveying sand from the bottom of the tank.

The receptacle 8 wherein classifying of the sand is carried out or accomplished is positioned in the tank 9 over the deep end of the latter. It is box-like as far as shape isconcerned and consists of a pair of side walls 24 and 25, an inner end wall 26, and an outer end wall 21. The two end walls are substantially equal in length to the width of the bottom wall l2 and the end wall l3 of the tank 9 and are Welded or otherwise fixedly secured at the ends thereof to the side walls 24 and 25. The side wall 24 fits against the inner face of the side H] of the tank and is provided at the upper margin thereof with an out-turned flange 28. The latter, as shown in Figure 3, overlies and abuts against the flange l5 of the tank side Ill and constitutes part of the means for holding the receptacle 8 in place. The side wall 25 of the receptacle fits against the side ll of the tank and is provided along the upper margin thereof with an out-turned flange 29. The latter is coplanar with the flange 28 and overlies and engages the out-turned flange l6 along the upper or top margin of the tank side H. It extends from one end of the side wall 25 to the other and constitutes another part of the means for holding the receptacle in place in the tank. A receiving hopper 30 for the sand and water extends acrossthe upper central portion of the receptacle 8. This hopper is adapted to receive the sand and water in stream form from the aforementioned trough, pipe or other delivery medium and serves to direct the sand and water downwardly toward the central portion of the bottom of the receptacle, as shown by arrows in Figure 6 of the drawings. A screen 3| extends across the bottom of the hopper and serves to eliminate leaves and other foreign matter from the sand and water prior to passage of the latter into the receptacle. A vertically extending partition 32 underlies the screen 3| and serves to divide the sand and water so that half flows into the outer end of the receptacle and the other half flows into the inner end of the receptacle. This partition extends between the two side walls 24 and 25 of the receptacle and is suitably secured in place by means of pairs of angle brackets 33. The lower portion of the partition is provided with a pair of opposed arcuate deflectors 34. The latter operate to direct the sand and water horizontally across the bottom of the receptacle, as shown by arrows in Figure 6. They extend between the side walls 24 and 25 and are substantially quarter cylindrical. The bottom of the receptacle is partially closed. by means of a series of side by side spring brass strips 35. The latter extend between the bottom portions of the end walls 26 and 21 of the receptacle and are arranged oneinclined downwardly in one direction and the adjacent one inclined downwardly in the opposite direction so as to form therebetween V-shaped troughs. The upper portions of the strips 35 are suitably se cured to brackets 35 which extend lengthwise of the receptacle and are secured at the ends thereof to the end walls 26 and 21. The lower portions of the strips 35 are provided with rows of transversely extending slots 31 and are adapted to flex downwards, as shown by dotted lines in Figure 4, in order to permit the sand which accumulates in the V-shaped troughs between the strips to pass or drop into the bottom of the tank 9. When the strips are in their normal or unflexed position the lower edges thereof abut against one another. As soon as the sandbuilds upon the strips 35 to the point where the weight thereof is suflicient to overcome the spring action of the lower portions of the strips it flexes the lower portions downwards into their open position and as a result the grains of sand on the strips drop through the bottom of the receptacle into the deep end of the tank and are there subjected to the conveying action of the two screw conveyors IT.

Th water and fine grains of sand are dislcharged from the receptacle 8 by way of four transversely extending flumes 38, 39, 48 and 4|. These flumes extend across the central upper portion of the receptacle and are suitably secured at the ends thereof tothe side walls 24 and 25; They are positioned above the transversely slotted flexible strips 35, as shown in Figure 6, and are adapted to have the water and fine grains or particles of sand flow into the upper open portions thereof. The ends of the flumes that are secured to the side wall 24 of the reservoir communicate with a U-shaped discharge nose 42 on the side ll] of the tank by way of openings 43 in the side wall 24 of the reservoir and a large opening 44 in the tank side H3. The nose 42 embodies an outwardly extending flange 45 at the inner edge or margin thereof and this flange fits against the opening defining portions of the tank side It). Rivets 49 extend through the flange 45 and the adjacent portions of the tank side H1 and the receptacle side wall 24 and serve to hold the nose as well as the receptacle in fixed relation with the tank. The

nose 42 is adapted to discharge into a trough (not shown) and as a result of the arrangement and design of the flumes the water, after flowing into the receptacle 8 by way of the receiving hopper 38, is discharged. As a result of the arrangement and location of the flumes the water together with the fine grains of sand therein flows upwards from the receptacle bottom after entering the receptacle via the receiving hopper 39, then passes into the flumes, and finally is discharged into the discharge nose 42 via the flumes. During flow of the sand and water in the receptacle 8 the coarse or heavy grains of sand accumulate on the flexible strips 35 and drop into the tank 9, as hereinbefore described, upon downward flexure of the lower ends of the strips and the lighter or finer grains of sand flow upwards into the flumes and are discharged from the receptacle via the flumes and the discharge nose 42. A bafile plate 4'! is interposed in the receptacle between the flumes 38 and 39 and causes part of the Water flowing into the outer end of the receptacle to flow into the flume 38 and the remainder to flow into the flume 39. As shown in Figure 6, the bafile 41 is disposed an appreciable distance above the bottom of the receptacle and, as shown in Figure 7, the ends of the baffle engage and are secured to the receptacle side walls 24 and 25. A corresponding bafiie 48 is disposed in the inner end of the receptacle.

This baffle 48 is positioned midway between the flumes 4|] and 4| and serves to direct a portion of the water entering the inner end of the receptacle into the flume 4| and the remainder of such water to flow into the flume 40. The ends of the baflle 48 are secured to the receptacle side walls 24 and 25, as shown in Figure 7. As shown in Figure 6 of the drawings, the sides of the receiving hopper 38 are joined to and extend upwardly from the upper marginal portions of the inner sides of the flumes 39 and 4D. In order to control or regulate the fineness of the sand which accumulates on the strips 35 and passes intothe tank 9 upon downward fiexure of the lower portions of such strips, the upper margins of the sides of the flumes 38 and 4| and the upper margins of the outer sides of the flumes 39 and 40 are provided with vertically adjustable weirs 49. These weirs extend between the receptacle side walls 24 and 25 and are secured to the flumes by means of bolt and slot connections 59. The latter consist of wing nut equipped bolts 5| on the flumes and vertically extending slots 52 in the weirs. By loosening the nuts on the bolts the weirs may be shifted vertically into any desired position. The top edge of the lowest weir determines the level of the water in the receptacle and the tank. When the weirs are in their lowermost position the water in the reservoir flows at a comparatively low velocity and uniformly into the four flumes. Under such conditions only the fine grains or particles of sand are carried by the Water into the flumes. If it is desired to carry off coarser grains ofsand so as only to leave on the strips 35 the extremely coarse grains of sand certain of theweirs are raised by adjustment of the bolt and slot connections for such weirs. Upon raising of certain of the weirs the water in the reser voir flows into the flumes over the lower weirs only and as a result the velocity of the water is so increased that the coarser or medium sized grains are carried by the water into the flumes and discharged via the flumes into the discharge nose 42. By adjusting the weirs it is possible to separate from the sand in the reservoir the extremely coarse grains or the extremely coarse and middle sized grains. The vertically adjustable weirs 49 constitute simple means whereby the apparatus as a whole may be controlled or adjusted to effect any desired classifying of the sand.

In order to permit of ready discharge of the foam which accumulates on the water in the tank as the result of the action of the screw conveyors H, a trough 53 is mounted on the inner end wall 26 of the reservoir. This trough extends between the two reservoir side walls 24 and 25, as shown in Figure 7, and has an inlet opening 54 for permitting the water in the tank to flow into it.

One end of the trough is closed by the end wall 25 of the reservoir and the other end of the trough communicates with the dischargenose 42 closed opening 54 constitutes simple means for ridding the tank 9 of any foam resulting from operation or drive of the screw conveyors l7.

Assuming that the screw conveyors I! are in operation and a constant stream of sand and Water is being delivered into the receiving hopper 3D, the operation of the apparatus is as follows: The sand and water upon entry into the hopper, flow downwards past the partition 33 to the bottom of the receptacle and then outwards towards the end walls of the receptacle as the result of the action of the quarter cylindrical deflectors 34. As the sand and water flow over the longitudinally extending strips 35 the coarse or heavy grains of sand accumulate on the strips and upon downward flexure of the lower portions of the strips due to the weight of the accumulated sand pass downwards into the deep end of the tank and are then moved upwardly by the screw conveyors I I along the bottom wall E2 of the tank until they emerge from the column or body of water in the tank and are discharged over the upper end margin of the bottom wall I2. The fine particles of sand due to the velocity of the Water are drawn upwards with the water and flow into the flumes 38, 39, and M and then pass with the Water through the fiumes into the discharge nose 42. As a result of the classifying action of the apparatus the coarse or heavy grains of sand are separated from the fine or light sand grains. If it is desired to separate from the sand only the extremely coarse grains certain of the weirs 49 are raised by adjustment or proper manipulation of their bolt and slot connections. Such action results in an increase in the velocity of the water in transit through the receptacle and into the flumes and causes the medium sized grains of sand to be discharged with the lighter grains into the discharge nose 42. By adjustment of the weirs any desired classifying of sand may be accomplished. When it is desired to rid the tank 9 of any foam on the top surface of the column of water therein it is only necessary, as previously pointed out, to raise the gate '56 so as to effect discharge of the surface water and foam into the discharge nose 42 through the medium of the trough 53.

The herein described classifying apparatus has proved in practice to be extremely eflicient. It

may be manufactured at a low and reasonable cost due toits simplicity and is practical in that the classifying action may be varied or controlled by adjustment of the weirs 49.

Whereas the apparatus has been described as being primarily adapted for use in classifying sand, it is to be understood that it is also usable to classify other granular material. It is also to be understood that the invention is not to be restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

Having thus described the invention, what we claim as new and desire to secure by Letters Patent is:

1. A classifying apparatus comprising an open bottom receptacle adapted to have liquid with granular material therein introduced into it and then circulated substantially horizontally in it, a series of elongated side by side flexible laterally inclined strips across the bottom of the receptacle, arranged to form V-shaped troughs between them for accumulation of the coarse grains of the material and having the upper portions thereof fixed and their lower portions free and adapted to flex downwards away from one another and permit such grains to pass from the apex portions of the troughs through the bottom of the receptacle, and a fiume associated with the receptacle and arranged to receive the liquid and the fine grains after circulation thereof in the receptacle and then discharge them from the receptacle.

2. A classifying apparatus comprising an open bottom receptacle adapted to have liquid with granular material therein introduced into it and then circulated substantially horizontally in it, a plurality of side by side flexible thin metal strips across the bottom of the receptacle, having certain of the adjacent side margins thereof fixedly secured in place and their other adjacent side margins provided with full length rows of transverse slits therein and adapted to have the coarse grains of the material accumulate thereon and to flex downwards and permit such grains to pass through the bottom of the receptacle, and a fiume associated with the receptacle and arranged to receive the liquid and the fine grains after circulation thereof in the receptacle and then discharge them from the receptacle.

3. A classifying apparatus comprising an open bottom receptacle adapted to have liquid with granular material therein introduced into it and then circulated substantially horizontally in it, and a plurality of elongated side by side flexible laterally inclined strips across the bottom of the receptacle arranged to form V-shaped troughs between them for the accumulation of the coarse grains of the material and having the upper portions thereof fixedly secured in place and the lower portions thereof free and adapted in response to the accumulation of sand in said troughs to flex downwards away from one another and permit such grains to pass therebetween and thence through the bottom of the receptacle.

4. A classifying apparatus comprising an open bottom receptacle adapted to .haveliquid with granular material therein introduced into it and then circulated substantially horizontally in it, and a plurality of elongated side by side flexible thin metal laterally inclined strips across the bottom of the receptacle, arranged to form V- shaped troughs between them for the accumulation of the coarse grains of the material and having the upper portions thereof fixedly secured in place and the lower portions thereof free and transversely slotted from end to end and adapted in response to the accumulation of sand in said troughs to flex downwards away from one another and permit such grains to pass therebetween and thence through the bottom of the open receptacle.

5. A classifying apparatus comprising a rectangular open bottom receptacle adapted to have liquid with granular material therein introduced into it and then circulated substantially horizontally towards its ends and then upwardly, a plurality of side by side flexible longitudinally extending laterally inclined thin metal strips across the bottom of the receptacle, arranged to form between them V-shaped troughs for the accumulation of the coarse grains of the material and having the upper portions thereof fixedly secured in place and their lower portions free and transversely slotted from end to end and adapted to flex downwards away from one another upon accumulation of the coarse grains in the troughs and permit such grains to pass therebetween and thence through the bottom of the receptacle, and a plurality of straight transversely extending fiumes of U-shaped cross section in the upper portion of the receptacle arranged to discharge through one side of the receptacle and adapted to receive the liquid and the fine grains after upfiow in the receptacle and then discharge them from the receptacle.

6. A classifying apparatus comprising a rectangular open bottom receptacle adapted to have liquid with granular material therein introduced into it and then circulated substantially horizontally towards its ends and then upwardly, a plurality of side by side flexible longitudinally extending laterally inclined strips across the bottom of the receptacle, arranged to form between them V-shaped troughs for the accumulation of the coarse grains of the material and having the upper portions thereof fixedly secured in place and their lower portions free and adapted to flex downwards away from one another upon accumulation of the coarse grains in the troughs and permit such grains to pass therebetween and thence through the bottom of the receptacle, and a plurality of straight transversely extending laterally spaced flumes of U-shaped cross section in the upper portion of the receptacle, arranged to discharge through one side of the receptacle and adapted to receive the liquid and the fine grains after upfiowin the receptacle and then discharge them from the receptacle.

'7. A classifying apparatus comprising a rectangular open bottom receptacle adapted to have liquid with granular material introduced into it and then circulated horizontally in the direction of its ends and then upwardly, a plurality of side by sid flexible thin metal strips extending longitudinally across the bottom of the receptacle and adapted to have the coarse grains of the material accumulate thereon and to flex downwards and permit such grains to pass through the bottom of the receptacle, and a plurality of straight transversely extending laterally spaced fiumes of U-shaped cross section in the upper portion of the receptacle and with certain of the ends thereof in communication with the receptacle exterior, provided on certain of the sides thereof with vertically adjustable weirs and arranged and adapted to receive the liquid and the fine grains after upfiow thereof in the receptacle and then discharge them from the receptacle.

8. A classifying apparatus comprising a rectangular open bottom receptacle provided across th central portion thereof with a receiving hopper for liquid with granular material therein and adapted to have such liquid and material circulate horizontally towards its ends and then upwardly, a series of elongated side by side laterally inclined longitudinally extending thin metal strips across the bottom of the receptacle, arranged so that they form between them V-shaped troughs for the accumulation of the coarse grains of the material and having the upper portion thereof fixedly secured in place and their lower portions free and transversely slotted and adapted to flex downwards away from one another and permit such grains to pass therebetween and thence through the bottom of the receptacle, and a plurality of laterally spaced, transversely extending fiumes of U-shaped cross section in the upper portion of the receptacle and with certain of the ends thereof in communication with the receptacle exterior, provided on certain of the sides thereof with vertically adjustable weirs and adapted to receive the liquid and the fine grains after upfiow thereof and then discharge the liquid and fine grains from the receptacle.

JOSEPH E. McCLOUD. ALBERT WILLIAMS. 

